Electromagnetic pumping device for pumping fluids



March 10, 1953 A. RYBA ELECTROMAGNETIC PUMPING DEVICE FOR PUMPING FLUIDS Filed Aug. 27, 1948 9 Sheets-Sheet l ll l I I l J L K M g. M We 0 4 My M w m N a 52 3 Z q RYBA March 10, 1953 ELECTROMAGNETIC PUMPING DEVICE FOR PUMPING FLUIDS 9 Sheets-Sheet 2 Filed Aug. 27, 1948 prroe/z/zx CE gM-l A. RYBA March 10, 1953 ELECTROMAGNETIC PUMPING DEVICE OR PUMPING FLUIDS Filed Aug. 2'7. 1948 9 Sh eets Sheet 5 INVENTOR.

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A. RYBA March 10, 1953 ELECTROMAGNETIC PUMPING DEVICE FOR PUMPING mums Flled Aug 27, 1948 A. RYBA March 10, 1953 ELECTROMAGNETIC PUMPING DEVICE FOR PUMPING FLUIDS 9 Sheets-Sheet 5 Filed Aug. 2'7, 1948 INVENTOR.

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19 frog/U5}? A. RYBA VIII/la ELECTROMAGNETIC PUMPING DEVICE FOR PUMPING FLUIDS March 10, 1953 Filed Aug. 27, 1948 March 10, 1953 A. RYBA 2,630,760

ELECTROMAGNETIC PUMPING DEVICE FOR PUMPING FLUIDS Filed Aug. 27, 1948 9 Sheets-Sheet 8 /75 I76 /50 I70 777 /75 fza Ell /7G. 27

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ELECTROMAGNETIC PUMPING DEVICE FOR PUMPING FLUIDS Filed Aug. 27. 1948 I 9 Sheets-Sheet 9 FIG. 30 F/& .3/

AM/rm/ ere/7 Patented Mar. 10, 1953 ELECTROMAGNETIC PUMPING DEVICE FOR PUMPING FLUIDS- Anton Ryba, Bolzano, Italy Application August 2'7, 1948, Serial No. 46,377 In Switzerland September 26, 1947 (C1. IDS-53) 28 Claims.

This invention relates to electromagnetic pumping devices for pumping a gaseous or liquid fiuid.

One of the objects of the invention is to provide a novel and improved pumping device of the general type, above referred to, by means of which a substantial volume of fluid can be rapidly and conveniently pumped with or without increase in the pressure of the fluid to be pumped.

Another object of the invention is to provide a novel and improved pumping device of the general type, above referred to, which comprises comparatively few and light moving components,

thereby greatly reducing the power required for pumping a given fluid volume'and simplifying the construction of the pumping device.

Another object of the invention is to provide a novel and improved pumping device of the general type, above referred to. all or most components of which can be simply and comparatively inexpensively manufactured, are reliable and rugged in operation, and can be rapidly and simply assembled or disassembled.

Another object of the invention is to provide a novel and improved pumping device of the general type, above referred to, by means of which a gaseous fluid can be pumped and compressed in several stages. This arrangement is particularly advantageous when a substantial end pressure is desired.

Further and other objects, features and advantages of the invention will be pointed out hereinafter and set forth in the appended claims forming part of the application.

The above enumerated objects of the invention and other objects hereinafter pointed out are attained by providing an electromagnetic pumping device in which an electromagnet and an armature are disposed within a housing including a pumping chamber, the volume of said pumping chamber being controlled by the armature position, said armature being arranged to oscillate in response to an intermittent energization of the electrcmagnet, thereby varying the volume of the pumping chamber accordingly, and in which fiuid admission means admit fluid to be pumped into the pumping chamber upon oscillatory movement of the armature in a direction for increasing the pumping chamber volume, and in which fluid discharge means discharge fluid from the pumping chamber upon oscillatory movement of the armature in a direction for reducing the pumping chamber volume.

In the accompanying drawings Several .now

preferred embodiments of the invention are shown by way'of illustration and not by way of limitation.

In the drawings:

Fig. 1 is an elevational section through a double acting electromagnetic pumping device according to the invention.

Fig. 2 is a top plan View, the upper housing portion and magnet body being removed.

Fig. 3 is an elevational section through a modifled pumping device according to the invention.

Fig. 4 is an elevational section through an electromagnetic single acting device according to the invention.

Fig. 5 is a plan View showing by way of example an outer or cover disc of the diaphragm armature.

Fig. 6 is a similar view of one of the intermediate discs of the diaphragm armature.

Fig. '7 is a plan view of one of the annular core elements of a magnet body.

Fig. 8 is a section along the line VIII-VIII of Fig. '7.

Figs 9 and l!) are similar sections of two modified annular core elements.

Fig. 11 is a sectional view of another modification of an annular core of a magnet body.

Fig. 12 is a plan view of the core of Fig. 11.

Fig. 13 is a sectional view of still another modification of a core element.

Fig. 14 is a fragmentary section of the core element according to Fig. 13, on an enlarged scale. 1

Fig. 15 is a sectional view of another modification of a pumping device according to the invention.

Fig. 16 is a plan view of- Fig. 15, the upper magnet body and the armature being removed.

Figs. 17 and 18 are fragmentary cross-sectional views of modifications of magnet bodies as may be used in a pumping device according to Fig. 15 and other figures.

Fig. 19 is a cross-sectional view of a magnet body as may be used in the pumping device according to Fig. 15, and other figures.

Fig. 20 is a plan view of Fig. 19.

Fig. 21 is a diagrammatic circuit system for the magnet bodies of a pumping device.

Fig. 22 shows the electric circuit connections for the magnet bodies connected to a single phase net, the circuit system including a series connected capacitor to obtain a certain phase shift.

Fig. 23 shows a typical circuit diagram for connecting the magnet bodies to a two phase net.

Fig. 24 is an elevational section through a mod- Fig. 29 is a bottom plan-=view -ofath rmagnet body according to Fig. 28.

Fig. 30 is one of the laminae out of which the cores of the magnet body are composed; and

Fig. 31 is a modified laminated-core of a magnet body.

The double acting pumping device for pumping liquid or gas, as shown in Figs. 1 and 2, comprises two casing halves 5 and 6 each housing a magnet body. Each magnet is-composedvof three annular cores I 2 and 3 :U shaped incross section and concentrically mounted. The cores mayberin'g shaped, polygonal or otherwise'shaped. They-are secured by rivets fi'to the respective casing haives preferably. made of non-magnetic material. The annular cores I, 2, 3 comprise term-magnetic material and should have at least one :radial 'slot 60 (Fig. 7) to reduce eddycurrentdosses; In the grooves of the annular ccres there are-disposed theexciting coils'l, 8and9; These exciting :coils are embedded in the open -groovcsbffthe cores into a mass of a plastic insulation': materialeof a type becoming very hard whom-dry... All thegrooves and radial slots-of .the' annular cores are filled with sucninsulating materialso-as-toiorm a smooth outer surface. A substantially spheri cally curved cup-shaped depression to form chambers IIland" I I, respectively; is then madein the surface of the magnet-bodies thus formed; preferably, the cur'vatu're of the two depressions is selected so as to :oorres'pond approximatively to the curve of deflection of the diaphragm-as will be more fully explained hereinafter. The two casing portions? and G-arese'cured together by means of screw boltsl 2.

A diaphragm operating in the: manner of a pump piston is disposed within :the hollow space formed by the two depressions I b and I I between the magnet bodies and heldalongrits periphery so that it is secured without vertical play'betw'een the two casing portions." The -diaphragm' com' prises advantageously several flexible discs or laminae'of ferro-ma-gneticmateriaL-th'e outer laminaeiaand I i-facm athe-cupsm and i I being preferably full discs, while the inner discs (or flllingrdiscs) i5 and-I 6 may be provided with radial slots 58; 59 (Fig; 6) to reduce: the-'eddy-cun' rent effect and to attain a better deflection: The diaphragm discs I3;-Id';- ifi and- I6- are held=to gether in the center-by. a rivetITwh'ichalso serves to secure a thin resilient'valve plate Iii-or I9 respectively-to each side-of the diaphragm. Eachvalve plate isprovided with radial slots to" form flexible valve sections. 7

The full cover discs 13=-and-l4 ot-the diaphragm includeaplu-rality ci -circularly disposed holes'fifi and 2! respectively each in-registry with'one of the segments -22 (Fig; 2) of the radially slotted valve plates I8 andifl forming suction valves to-= gether with holes ill-and 2i a To preventa relative-rotation of the valve plates and the-diaphragm discs during operation, rivet I'iand the corresponding: central holes inthe valve plates and diaphragm discs are-unround-forexample square. The radial slots 58 (Figs. 2 and 6) of the filling discs i5 and I6 are extended so far towards the center that they can register with the holes 23 or ZI of the cover discs I3 and I4.

The two chambers I I) and I I on each side of the diaphragm may be additionally sealed along the periphery of the diaphragm by resilient sealing rin'gs 23 and 24 which ar iclampjed between the two casing portions andthe diaphragm.

To enable the diaphragm to fit itself snugly into the spherically curved bottom of each depression in spiteof -the valve plates I8 and it on both sides of the diaphragm, each of the magnet bodies is provided with a corresponding circular recess '25' and 26 respectively into which the valve plates mayenter.

Discharge valves" 21 and 28 for discharge of the fluid to be pumpedv are secured to each casing portion 5 and 6 by screwing the valves into the centers of the casing portions. Outlets 29 and 33 from the 1 two chambers-4 0 -and I i are controlled byvalve-plates di and-32, respective1y of the valves. The plates are biasedupon their seats by springs 33- and- 34 The fluid to be-pumpedis'admitt-ed into the compressor through" a tube-35 communicating with an annular space 35 between the two casingportions; Itflowsthroughcthe -radial slots 53 of the filling discs i5'and lfi -of the diaphragm until it reaches openings 20 and 2| normally closed by platesIB-and I9;

In connection-it should be mentioned that in prin ple only two-full-unslotted cover discs Hi (Fig. 5) are. required-for the diaphragm.

The number oi-the flllingediscsiFig-ofi) should be selected-accordingato the required thickness and rigidity against deflection of the diaphragm. The total-thicknessshould be so d-imensionedthat full use of the- -fiux of the 'magnetic circuit is obtained. In regardto: the rigidity of the diaphragm-,- general'l-yspeaking; shallow depressions and higherfluid-pressures-require greater rigidity while increased: concavity:- and :lower fluid pressures require a softer-diaphragm; The necessary rigidity of the-diaphragmcan be conveniently obtained by suitably. selecting-the thickness or? the various lamin'aeoutofwhich the diaphragm is composed; 'I-h .magnetic materialusedfor the discs-io at least some ofithem should possess.

I besidesuseful magnetic qualities, also good mechanical and elastic properties; Materials which have these properties are well known in practice.

The design-of the current :coiinecting terminals fortheexcitingfcoilsl. 8"'-and Smay be conventional, and it is believed that-a detailed showing is not essential forthe: understanding of the invention.

The diaphragm pumping; device=according to Fig. 3 is distinguished from the' one of Fig. l in that nosuction valves iplates I6, I53) are provided. A" diaphragm 3-?is so' inserted between the two magnetbodies formed-by annular cores I, 2, 3and excitingscoilsa bfi, .H that itscircular edge can make a smail vertical play, whereby an annular slot is fornied' al'ong-th'e' outerperiphery of-the diaphragm-alternatelyon the top' and on the'bottom face=thereof depending upon the direction in which the diaphragm" is flexed as will be more fully 'explained'hereinafteri As a result, fiuidcanenter into the respective one of charmbers-floor. 39. The sealingiloflthese two chambers along'the marginal' portiorr-of the diaphragm effected at the required 'moment'by the magnetic force urging the -diaphragm toward and against the pole-surfacesof the magnet-bodies.

The different laminae of the diaphragm are held together along the edges thereof for example by means of a collar ill of sheet metal. Of course, care must b taken that the edges of the laminae or discs are held in such manner that relative displacement and deflection of the several discs are not prevented. The diaphragm is advantageously composed of a plurality of filling discs I5 (according to Fig. 6) and two full cover sheets I3, I4 (according to Fig. 5) but without circularly disposed holes 26. As will be apparent, slots 58 in this embodiment merely serve to reduce eddy current losses and to increase the flexibility of the discs but not as conduits for fluid. The discs of the diaphragm are held together at their center by a rivet 4|.

Fig. 4 shows a single acting magnetic pumping device similar in its essential parts to the one shown in Fig. l with the difference that only one magnet body comprising annular cores I, 2, 3 and coils l, 3, 9 is provided. Accordingly, a diaphragm 45 is attracted in on direction only by magnetic forces and no magnetic forces are available to return the diaphragm. The diaphragm 56 must spring back by its own resiliency and where this is not sufficient an auxiliary spring ll may be provided. This spring is suspended in a casing portion 55 and connected to a rivet 49 which unites the various laminae of the diaphragm. Fluid is admitted through an intake nipple 5i! and discharged through a valve SI. The cover portion 58 of the casing is secured by screws 52 to a lower casing portion 53. All other parts are in principle arranged as in Fig. 1 and are clearly shown on the drawing.

Instead of assisting the return stroke of the diaphragm by a spring, a second magnet body may be provided which exerts the function of the spring 4?. This magnet body, as it does not effect any delivery work can be dimensioned correspondingly weaker.

Fig. 6 shows by way of example one of the diaphragm filling discs (I5). While the two outer or cover discs I3 and I4 (Fig. 5) facing the curved. surfaces of the magnet bodies consist advantageously of resilient full discs, the intermediary discs I5 and it which serve primarily to provide the necessary thickness of the diaphragm for conducting the magnetic flux, are advantageously provided with as many long slots 53 and short slots 59 as possible to reduce the influence of the eddy current effect and to make the discs more flexible. The slots can be arranged in any desired shap and manner, but care has to be taken that the magnetic flux of the magnetic circuit is not interrupted or appreciably affected. It is further advantageous to group the radial slots in such manner that the circular continuity of the material is interrupted and as few as possible closed concentric passages of material remain. In this manner, bending and warping of the discs by heat tensions or the like are effectively countera-cted.

Figs. 7 to 10 show several modifications of the fl-shaped annular cores of the magnet bodies. As previously mentioned, the several cores are advantageously at least once radially slotted (6B) for the purpose of reducing the eddy current losses; in case, a single slot is not sufficient to eifectively reduce the eddy current effect, several radial slots may be provided. It is not necessary to sever th ring cores into segments. Small transverse sections of the material may remain so as to retain each core as single element. The

more an annular core element is slotted, the more the eddy current effect is reduced.

Fig. 8 shows a section through a core element which is once radially slotted (at Eli) and further provided with several radial slots 54' which do not completely traverse the element.

It is advantageous for an efiicient operation of the described magnetic pumping devices to provide for the greatest possible flux density of the magnetic field at the pole surfaces causing a magnetic constriction in the shanks of the annular U-section cor elements. For this purpose, the sectional area 55 of the core shanks is increased with respect to the pole surfaces 56 (Fig. 9), so that in spite of the influence of the magnetic stray field no narrowed path for the magnetic flux is caused. Instead of making the pole surfaces narrower according to Fig. 9-, it is also possible to provide a lining 51 (Fig. 10) of ferro-magnetic material, whereby the same is obtained.

Any magnetic material is suitable in principle as material for the annular core elements, however, it is to be recommended to use an iron silicium alloy as known in the construction of electrical machinery for instance for dynamo sheets.

The number of annular cores and corresponding exciting coils out of which a magnet body is composed can be selected as desired within a Wide range. The thickness of the diaphragm can be reduced by increasing the number of an nular cores forming the magnet body.

Two other modifications of an annular magnetic core are shown in Figs. 11 to 14. According to Figs. 11, 12 and 14, the core is formed by an annular member of U-section, composed of three single annular elements I30, I3I, I32 fitted one into the other. The innermost element I32 has slightly shorter branches than the other two elements the branch faces of which form the pole surfaces. The three single elements consist of magnetic material, preferably of alloyed dynamo sheet material and are electrically insulated one with respect to the other, as it is well known for laminated iron cores. The insulating layers are designated by the numeral I34 in Fig. 14. The exciting coil (not shown) is inserted into the annular groove I33. The various single elements its, HI and I32 may be held together by a rivet I35.

In the example according to Fig. 13 the annular core comprises also three distinct annular U-shaped elements I36, I31 and I38. The branches of all elements extend in this modification to the pole surfaces.

As seen in Figs, 11, 12 and 13, the annular core is radially slotted, the slot I 39 traversing the entire width of the elements to reduce the eddy current effect. Additional radial slots may be provided which do not completely traverse the core, as shown in Fig. 8.

The number of single elements of which the core is composed can be selected as desired. The effects of eddy currents can be the more reduced the greater is the number of individual core elements.

The radial slot I39 prevents closing of the path of the eddy currents formed in the core in a continuous circular path in which case the core would act as a short-circuited secondary coil. By reason of the radial slot in the core, the paths of the eddy currents must reverse themselves at the slot so that for the entire eddy current loop only the difference of the potentials induced in the inner and outer layers, respectively, of the core;cambeeomezefiectivesas felectromotive force of the loop.

The separationiofi.thezannularcoreinto :several singleiannularielements hasithepurpose or rendering: thementioned 1.difference .in. induced. potentials as small aspossible; in.v that the current loopiwhichimust be formedwithlneach. individual element is constricted.according, to the thickness of theelementprofile." As a result, the difference in potential between the'inner and outer surface layer decreases in proportion to the thickness of the: individual elements: of;thecore .when. these latter: are-electrically"insulated" one from the other;

The eifect'of the element)! (Fig. 14) having shorter: branches sthan. the two: other. elements is that the-magnetic flux: which is increased by theilea'kage or; stray: field in .therannular grooves and. which ;in turn: increases .the magnetic saturation from the pole surface towards the bottom of the grooves, provided the thickness of the branches WOllldibB constant, can becarried without;decreasing:the 'saturation' at the pole surfaces.-.. Moreover; the element. i32 cannot only carry the magneticstray flux, but also permits to obtainanydesired ratio between the magnetic saturation at the polesurfacerand in the branches of the core elements;

The pumpinggdeviceaccordingto Figs. 15 and i6 is'in many respects similar'to'the pumping devices as-previously: described. According to Figs. 15 andlfi, .the housing isooinposed of two cup-shaped sectionsZZt-and 22! held together by. bolts and nutst222. CoiLspringsZES may be employed-to'provideiia certain elasticity between the sections of .the:.housing. Each section houses a magnet body 2.24 amaze: respectively made of ferrot-magneti'cmateriah Thetwo magnet bodies are 1 each provided. with'sthree concentric grooves inwvhich.theiexeitingxcoilsr226; 221, 228 and 2311, 21: i 2.32, respectively are. inserted.

Theremainingspaoe in the. grooves is again filled with 'a suit'able insulation material so that smooth curved surfacesv are formed at the pole iaces'the-pole faces-of each magnet body forming a; pumping chamber with the adjacent side of an armature 233. This armatureis again shown as a diaphragm'composed of several flexible discs made of term-magnetic material and held along its periphery between the housing sections. A sealing ring ZMmay; be-providedrto secure fluid ightnessibetween. the housing, sections. Fluid is admitted intozpurnpingjchamber 235 by means of an inlet valve 236-. which communicates with a duct 231. This duct.- issues. into a plurality of channels-238- leading: into pumping chamber 2525. The admission otfluid. into pumping chamher 235 is contrclledsby a-suction'valve comprising a flexible-.cup-shapedvalveplate 233. This vaive platenormally closes: channels 238 and is lifted off these channels. by the suction of. a vacuumithat is.created in pumping chamber when diaphragm 523-3 .iseattracted' toward magnet body 225;

For thepurpose of: discharging fluid from. pumping chamber 235 a discharge valve. 2 :8. is. provided- This valvecomprisesa valve member 2 normally pressed by aspring 232 against a duct 2-53 leadinginto pumping chamber 235. As a result, duct-.243 isnormally: closed but is opened when valved .is'i'lifted offits-seat by increased pressure: in chamber. il fitinresponse to the. attraction of diaphragm .233toward magnet body Fluid admissionaintoiand fluid .dischargeironr.

the second-:pumping; chamber 2 M is similarly controlled by inletvalve: means 245 and outlet tion material to retain a smooth surface at the pole-faces.

Each of the magnet bodies 22 i and 225 isdivided-by' radial slots 225i into sectors for the purpose oireducing eddy-current losses.

on inner continuousring 252.

The fragmentaryviewof 17 shows a magnet body distinguished. from the magnet bodies of Fig; 15 by providing U-shaped inserts EE-Smade of ferr c-magnetic material in the coil grooves; Fig. l8showsa magnetic body 22 t with grooves fibe and-.256. The purpose of thesegrooves i iand 256 is to increase furtherthe flux density-at" theipoles, and to separate, at

least to'accrtain'extent, themagnetic circuits producediby the individual. coils.-

The magnet body as. shown in Figs. 19' and 20 is distingnishedpfromrthemagnet bodies of Figs: 15 and 16 by providing" completelyseparated sectors which are held-together by a, ring 269 encompassing the individual sectors rather than by a ring such asring' 252.fo'rmed by the material of themagnet bodies proper: Ring fitfi'may be shrunk upon the sectors'andm'ay be slightly conical at the inside to'securethe ring upon the sectors.

The individual sectors :as. shown'in Figs. 16 and 2c may be insulated irom each. other.

It should be noted inthis' connection that'it is of course alsopossible to provide less or more than three coils for each magnet body. As. a result, eachicoil with its ferromagnetic core material forms an independent magnetic circuit. Furthermore, the design according to Figs. 15 to 2d is not limited' to a circular shape but any other suitable cross-section may be provided.

Referring now to the operation. of the armature; the same, when oscillated, alternately- SUCKS a certain quantity of fluid admitted through intake nipple 35 into one of the chambers it or" i i (Fi 1), or 38; 39' (Fig. 3), and expeils'it therefrom'through one of the discharge valves 2?; 28';

To avoid partial back-flow of the fluid suckedin by reason of improper: timing of. the opening and closing of the chamber intake and discharge openings of the chambers, iorinstance'in the embodimt-rntv according'toFig. 3, or to obtain maximal magnetic attraction as'caused by the individual coils orcoil'groups of the magnet bodies at predetermined time intervals, the exciting coils can be connected in two or more groups for each magnet. body. Each group is then excited by aperiodically acting alternating potential, preferably in such manner that an outer group of coils acting upon the marginal portions of the diaphragm is energized by a currentwith a phase lead with respect toan inner group of coils. This shift in phase can be obtained by any suitable phase shifter for example in single phase nets by aoapacitor C (Fig. 22) connected in series, and in polyphase nets by connections to several phases (Fig. 23) as will-be more fully explained hereinafter.

The connectons of theindividual exciting coilsin each magneti'body may be so made that the direction'of current is" reversediini the'ooils-. of

These re' cessesisilare preferably also filled with insula-- The sectorsthus formed are held together by retaining 9 adjacent annular cores and that the direction of the current fiow in the corresponding exciting coils of the upper magnet body and in the lower magnet body is opposite. As a result, the magnetization of the diaphragm during the alternate excitation of the upper and the lower magnet body is not reversed and the iron losses of the diaphragm are thus reduced.

Suitable connections are shown in Figs. 21, 22 and 23. The arrows a indicate the direction of the magnetic flux for each annular core element, and the marks in the coils (circle with point and circle with cross) indicate the direction of current in the respective coil.

While Figs. 21, 22 and 23 represent suitable circuit diagrams, there are various possible modifications, which are known to any person skilled in the art.

In the diagrams, K indicates the upper and K the lower magnet body; a single phase alternating current generator (Figs. 21 and 22) is designated by W; and a double phase alternating current generator (Fig. 23) with W. G and GI indicate the rectifiers in the one phase net of Fig. 21, R and S the main lines from the generator, G2, G2 and G3, G3 are the rectifiers in Fig. 22; G4, G4 and G5, G5 are the rectifiers in Fig. 23; R, R, S are the main conductors in Fig. 22; and R, Q, S the main conductors in Fig. 23; M are cut-out fuses; and C is a capacitor in Fig. 22.

The operation of a double acting diaphragm compressor or pumping device according to Fig. 1 is as follows:

When the compressor is connected to an alternating voltage according to the diagram of Fig. 21, the rectifiers (each group of coils must be connected to a rectifier) G and GI let each pass one half wave of the alternating current; accordingly, during each half period the lower and the upper magnet body are alternately excited. Magnetic attraction forces are thus created which pull the diaphragm alternately in opposite directions. Since the diaphragm is resilient and flexible, it is flexed by the magnetic attraction with one of its faces toward or against the curved surface of the excited magnet body, whereby at the same time a partial vacuum is formed in the chamber ill or H bounded by the opposite face of the diaphragm so that gas or liquid is sucked through the annular space 36, the radial slots 58 of the filling discs l5, l6, and the temporaril uncovered apertures 20 or 21 of the respective cover disc 13 or M into the respective one of the chambers or H, the suction valve plate I8 or I9 (accordingly, whether the diaphragm abuts against the upper or lower magnet body) opening by the action of the sucked-in fluid.

Let it be assumed that the upper magnet body is excited, then first the outer marginal zone of the diaphragm is attracted since the air gap is smallest in this zone. Hence, induction and the magnetic attraction are highest while towards the center of the magnet body the magnetic force decreases rapidly. By reason of the strong magnetic force exerted upon the marginal zone of the diaphragm, the latter will be attracted first along this zone and produce a reduction of the chamber volume, at the same time slightly compressing fluid in the chamber and slightly bulging the diaphragm. As a result of this bulging starting in the marginal zone of the diaphragm, the air gaps are successively reduced fromthe exterior toward the center. Accord- 'ingly, the action of the magnetic attraction forces acting upon the diaphragm also increases towards the center thereof simultaneously with the corresponding increase in the compression of the sucked-in fluid. When a predetermined pressure is obtained, the pressure valve plate 3| opens against the action of spring 33 and the discharge begins which is ended when the diaphragm is attracted into contact with the bottom of the magnet body. At the same time, new fluid is sucked into the other chamber ll.

At the time the fluid has been expelled from chamber 10, the lower magnet body becomes excited and by reason of the alternating periodic excitation of the two magnet bodies the cycle repeats itself according to the frequency of the half waves of the applied alternating potential, one side of the diaphragm always sucking and the other side compressing and expelling.

The operation of the compressor according to Fig. 3 difiers from the one according to Fig. 1 only in that admission of the fluid to be supplied into the suction and compression spaces 38 and 39 is effected without a special suction valve. The operation is as follows: As already mentioned, the diaphragm is mounted between the magnet bodies so that its marginal portion is held with a small vertical play. When the diaphragm is flexed for example toward the curved surface of the lower magnet body an annular slot is formed on the opposite side of the diaphragm along the outer circumference of the outermost annular core I, through which fluid is sucked into the upper chamber 38. When the upper magnet body is now excited, then first the outer marginal zone of the diaphragm is attracted, since the air gap is the smallest in that zone and the chamber 38 is thereby closed. The further operation is the same as described with reference to Fig. 1.

The arrangement of the electromagnetic coinpressor according to Fig. 3 is particularly suitable for liquid pumps, since a continuous flow of the liquid is created without reversal of the direction of flow.

In Fig. 1 and also in Figs. 3 and 4 the arrows indicate the direction of the fluid flow.

In the electromagnetic compressor according to the invention, the electric connections can also be made as shown in Fig. 22 in which the exciting coils of each magnet body are arranged in two groups in such manner that the outer coil group operates with a phase-displacement relative to the inner group. This is advantageous for the compressor according to Fig. 3, to prevent, as previously mentioned, a back flow of the fluid out of the chambers 38 or 39 in case the marginal slot does not close in the correct moment, and in the other described examples of the compressor to obtain a progressive bulging movement of the diaphragm from the edge towards the center.

The diagram of Fig. 22, in which phase shifting is obtained by connecting capacitor C in series, possesses in certain instances further advantages in connection with the compressor according to Fig. 1 as it allows to obtain a forced travelling of the field wave from the exterior towards the interior.

The electric function of the diagrams is as follows:

Fig. 21 (connection to a single phase net): When the alternating potential has for example momentarily a direction RS, a flow of current is possible only through the rectifier GI, and the become :lower magnet body is excited; Whenthe potential is reversed, the current flows through the rectifier G and the upper magnet body is excited.

This operation is repeated in-acoordance with the -periods of .the applied alternating-voltage.

Fig. 22 (connection to a single phase net'having an auxiliary phase connected through a capacitor): When the alternating potential has for example the momentary direction -RS, the rectifier G2 (central zone) passes the corresponding half wave. The potential R-S leads in phase relatively to the potential -RS--by reason of the capacitor .C, that is, the rectifier G2 controlling the marginal zone of the diaphragm passes also a half wave though'slightiy shifted in phase and leadingrelativeto the halfwave for the middlezone of the diaphragm. In other Words, in the central zone, the electromotive force acts upon an inductive impedance and in -themarginalzoneupona capacitativeimpedance.

Hence, when-the 'coil group associated with the marginal-zone is energized and begins toattract the diaphragm inthe marginal zone, the coil group associated with the central zone ofthe op- "positemagnetbody-isstill energized and attracts thecentral-zone of the diaphragmin opposite direction. .In this manner, the opening and closing of the suction slot formed along the outer edge of the diaphragm takes place at the correct moment withoutback flow of the fluid towards the l suction chamber sfi 01- 43, and a field Wave is created progressing from'the exterior towards the center of the diaphragm.

'The same effect-as obtained-withan auxiliary "phase according to the diagram of Fig. 22 canalso ceives its half wave-a quarter'of a period earlier -than-the inner coil group. Since the connected inductive-impedances are approximately equal, the currents are lagging relatively to-their voltages With about the same angles, and the relative phase shift between the outer'and inner coil groups will-alwaysbe approximately --90. After one hali'period, the voltages have changed their 'sign, and now the corresponding coil-groups of the "lower magnet body become eifective in quite analogous and-symmetric manner.

"The operation with phase shifted excitation and connection of the compressor to a polyphase net is-the same as when an auxiliary phase is artificially formed by interposing a capacitor. It

Will-be obvious-that various phase shifts can be obtained by means of different impedances for the outer and the inner coils or coil-groups obtainable by providing chokes and capacitors.

'The single acting magnetic pumping device "or compressor according to Fig.4, in regard to electrical and magnetic operation, will function'in "principle in "thesame manner as has "been described with reference to the compressor of Fig. 1. Current is supplied through rectifiers with or "without an auxiliary phase; analogous connections to one phase or polyphase nets are also possible. Of course, connections are necessary for only one magnet body.

When the magnet body according to Fig. 4 is excited there is created a magnetic attraction forcewhich'. attracts the diaphragm 46, compressing nuid in chamber 6|. The trapped fluid is discharged through the pressure valve-i. As

'---the actionof'the'magnetic traction-forces ceases:

side of the diaphragm is effective.

the margin toward the center.

the applied alternating cur-rent.

to fill the chambered l The suctionand compression stroke or" the diaphragm is repeatedperiodically according to the hitermitting excitation of the magnet body.

The single-acting magnetic compressor according to Fig. 4 cantbe connected to an. alternating current. source without including rectifiers (con- .trary to the compressors according toFigs. 1 and 3) when the return of the diaphragm is not effected by magneticforces but by a. spring force only. In such case, an oscillatory magnetic field is created,..the attraction forces of which have two maximum andtxvozero values ioreach current period. :Hence, thediaphragmis twice attracted during one fullpcurrent period. Accordingly, two suction andpressure actions are'obtained, that is, the number of; strokes of the diaphragm, without using rectifiers, is always :double the frequency of theapplied alternating potential.

The operation of the pumping :deviceaccording to Figs. 15 and 16 wiil be easily understandable from the previous specification so 'thatit need not be described in detail. It suifices to say that the armature isalternately; attracted byathe magnet bodies, the attraction progressing from As a resultpthe twopumping 'chambersztaand 264 are alternately iiiled through valves 236 and Ethanol alternately emptied-through va'lvesufi iii and 2%.

The periodic excitation of the magnetbodies can alsobe obtained by using'direct current and providing suitable control switches to effect closure and opening .of the magnet body circuits. The operation with directcurrent and control switches .is quite similar to the operation with alternating current and rectifiers.

The individual coils orcoil+groups can l ne-successively connected and disconnected-and the same efiec-tsare obtained aswith polyphase connections or with the creation of an auxiliaryphase by means ofa capacitor.

It has been found that the number of oscillations or" the diaphragm, that isthe number of strokes is the same as the numberof periods of In many instances the normal net frequency, usually-59 won periods per second, results in an-undesirablyhigh number of strokes, particularly for largercompressors. In such event, the frequency may :be stepped down by means of periodv transformers as are Well known in theelectric art.

Figs. 24-;and 25 show a modified compressor "in which the two casing portionsRand-.fiarsxprovided with cooling ribs $4 and confine each an annular recess 65 housingannular magnet cores 66, 51, and 63, 69 respectively. These magnet cores have a U -shaped cross-section andv are made of ferromagnetic material. .The-;cores-.support exciting coils i8, 11 and 12,i3,xrespectively;in their respective grooves, said coils :beinguembedded. in an 'insulationtmaterial. Hi8 sucinas plastic. The two'casing por tionsj and-5.6 are each provided with a cylindrical central bore i l .lined with a cylindrical sleeve'llfi and T6, respectively. A circular diaphragm preferably composed of twmor morezfiexible disos 'il and lii of ferromagnetic material serves as armature and is clamped with its edge between the two casing portions at H. The armature has a central opening traversed by a piston rod E9 on which are mounted two pistons 80 and 8! each disposed on one side of the armature discs ll, '58. The pistons are provided with normal piston rings 82. To form suction valves, each piston includes circularly disposed holes 83 and 84 which are closed and opened by the deflection of springy plates 85 and 85 held in position by flanges on the central piston rod 19. The plates are deflected by variations in the gas pressure and the kinetic energy affecting the plates. Recesses 3'! are provided in the casing portions and 5 to receive the flanges of the rod 19 and plates 85, 86 to limit the dead space in the compressor to a minimum.

The armature ll, 18 is advantageously provided with radial slots 88, 89 extending over the portions of the armature discs affected by the magnetic flux. The slots serve to reduce the eddy current losses and also to increase the resiliency of the discs. Fluid is again admitted through intake 35 and can enter chambers ill and ii through the circular slots formed between the discs and the outer cores, as described in connection with Fig. 3. The provision of an arma ture composed of several discs has the additional advantage that relatively silent operation can be obtained in spite of the impact of the armature, when attracted, against the magnet bodies since then elastic forces become efiective which greatly reduce the shock. When the armature is formed of several discs, the different discs are never absolutely even and plane. As a result, small tensions are present producing a certain yielding movement of the armature result ing in the mentioned noise reducing effect. Furthermore, the construction of the armature out of several discs permits an easier flexion thereof, even when the armature is relatively heavy.

Fig. 2c shows a single actin piston compressor according to the invention. A single piston H0 is rigidly connected to an armature ill. The casing comprises two portions H2 and H3, the lower portion H3 housing a magnet body. To assist the return of the armature Hi after attraction thereof by the magnet body a return magnet may be provided or a return spring [14 may be connected to the armature and suspended in the cover portion ii? of the casing. Spring H4 is necessary when the inherent springiness of the armature mounted in the casing in the same manner as the armature in Fig. 24 is not sumcient to cause rapid return of the same.

Fig. 27 represents a diagram of the electrical connections suitable for instance for a compressor according to Fig. 24. The two magnet bodies are designated with K and K and the diagrammatically represented armature with A. A source of alternating current W feeds through the maximum current switches or fuses M the two conductors R and s of the single phase net. The connection of the several exciting coils E, E for each magnet body is made so that the direction of the flow of current changes each time between one element and the adjacent one; moreover the exciting coils E of the upper magnet body are so connected that each opposite exciting coil E of the lower magnet body is traversed by the current in opposite direction. The circuit connections are clearly shown in the diagrammatic circuit of Fig. 27. The arrows indicate the direction of the magnetic flux, and the signs inthe annular spaces (circle with point and circle with cross) indicate the direction of: flow of the current.

The operation of the double acting electroma netic piston compressor according to Fig. 24 is as follows:

When the compressor is connected to an alternating voltage according to the diagram of Fig. 27, rectifiers G and G each pass one half wave of the alternating current. Hence, the lower and the upper magnet body are each excited for the time of one half period. In this manner magnetic traction forces are obtained which alternateiy pull the armature in opposite direction. Since the armature l1, 18 according to Fig. 24 forms a flexible diaphragm it will be alternately pulled toward the curved bottoms of the respective chambers 10 and l I and the pistons will oscillate in unison with the armatures. As a result. the suction valves alternately fill the upper and the lower cylinder space and the sucked-in fluid is alternately expelled through the pressure valves 27 and 28. The suction and pressure operation is periodically repeated according to the intermittent excitation of the magnet bodies.

The operation of the single acting compressor according to Fig. 26 is in principle identical with the one according to Fig. 24, according to whether the armature Ili carrying the piston is with its edge mounted in the casing or is freely oscillating.

The connections of the exciting coils I'll, I78 are also in principle the same, with the difference that only one connection for the one magnet body is required.

The single acting magnet compressor accordin to Fig. 26, contrary to the double acting com=- pressors according to Fig. 24, can be connected to an alternating current source without the inclusion of a rectifier when the retraction of the armature is not eifected by magnetic forces but by a spring, in which case an oscillating magnet field is created in which the magnetic forces have two maximal and two zero values per current period. As a result, the diaphragm armature is twice attracted during each full current period so that the suction and pressure actions are efiected twice. In other words, the number of strokes, without using current rectifiers, will always be the double of the frequency of the applied alternating potential.

Figs. 28 to 31 show six laminated magnet cores H1, H2, H3, Ht, H5 and He radially disposed in star-shaped relation in a circular casing H'i formed advantageously oi": non-magnetic material. The laminated bodies are provided with transverse grooves H8, H9 and I29 so positioned that all grooves of the bodies lie in the outlines of several con-centric polygons. In these grooves, three polygonally-shaped coils IZI, H2 and I23 are inserted.

The iron cores l i i to l I B and the coils are embedded in an insulating mass I25 such as a synthetic resin substance or a plastic, so shaped that a magnet body is formed having a shallow curved depression 24 in which oscillates the diaphragm (not shown).

To maintain the inactive spaces of the magnet body betweenthe laminated cores as small as possible, the core discs may be stepped as shown in Fig. 31; there may be provided one or several steps.

Any desired number of core disc packages may be provided. The casing H1 need not to be necessarily of circular shape. but can be adapted for example to the olygonal shape of the exciting .iaesomo 3 15 1; coils yfonexampleawhen only two laminatedcores are USEdfAthBJmQQQIIBtZbQdY. can be ,of rectangular shape.

rwhile theinventionhas'beenidescribedin detail with respect :to .:certain now-preferred examples and embodiments of the invention it willzbeunderstood :by those skilled inthe art aftenunderstanding theinvention, that various changesand modifications may ,be made without departing from. the spiritandscope: of. the inventionand it .isintended .therefore, .to coverzall such :changes 7 and modifications in .theappended claims.

-W;hat,is claimed is:

1.. In ;an 1 electromagnetic pumping .devicefor pumping. afluid; ,incombinationa housing, e1ec- "tromagnetic means: mounted therein, said .electromagnetic .meansrcomprisinga; plurality of: concentrically apdisposed electromagnetic gmembers each including gaj ferromagnetic core having a poleface. and an; exciting :coiL: the: adjacent coils and pole faces .oisaid; coresiorming asubstan- :tially continuous :surface, armature means .in form ofwa .fiexible circular 3 diaphragm, said .:diaphragm being arranged within. the. housing. in. a

position, relativeto' the diaphragm: so as .to form a, pumping .chamberrbetween the diaphragm and an adjacentv continuoussurface, electricalrmeans for. alternately. andintermittently energizing said coils progressivelyironr the. outermost: coil to. the

innermost'coiL sons to causev the .diaphragm to oscillate thereby varying the capacity of: said "chamber, said; coils .of1the. electromagneticmeans, "when energized, ;attracting 1corresponding .ad-

jacent circular surface areas of theidiaphragm :in I the. sequence of the:energization orthe; coils,

fluid admissionmeansarranged: to communicate with said.- chamberiand to admitrfiuid into i, the chamber upon oscillatorymovement.of the arma- .:ture means :in. .onegdirectionrelative to said: surface,..and' fluid discharge. means arranged to: com- :municate with; .said. chamber and .to 1 discharge fluid itherefromzupon' oscillatory-movement of .the .armature meanszin :opposite direction.

:2. An". electromagnetic; pumping device .as ide- .scribed in :claim .1', wherein said diaphragmcomprisesaplurality ofstackedfiexible discs,iatileast one. ofsaidzidiscsmade'of. ferromagnetic material and; having ;.at ileast one'ira'dial; slottto; reduce J eddy-current :losses.

3. An electromagnetic pumpingxdeviceas. de-

scribedxin. .claimlywhercinsaid housing is: vcomposed of two: portionsiforming an-.annu'lar1peripheralslottherebetween leading-into the pumping chamber, and wherein said diaphragm isheld withrplayxalongiw periphery. in. said slot .hetweenxsaidhousing portions so as to .closesaid chamber:uponoscillatory.movement of the diaphra-gm' toward the electromagneticmeans and to opensaid slot'upon oscillatory movement of the diaphragm away from the electromagnetic tance between :the; diaphragm and said curved.

surface decreases from the center of the.;diai phragmtoward the periphery thereof when the diaphragnbis in an; unattracted: position.

; 5.' .An' electromagnetic; pumping device; as de- 16 #magnctic cores .ahas "a substantial y :fl-rfihapc cross-section,- the open side 1oteach:core facing .the diaphragm and receiving the respective exciting coil, said -cores being slotted to reduce eddycurrent losses.

26. An electromagnetic;-.pumpingdevice as described in claim 1, wherein each of the said ferromagnetic cores has :a substantially U-shaped cross-section so as to form two side arms, the cross-sectional ,areaof the sidenarms of said cores being larger at the bottom of the cores than near the pole faces.

7.An electromagnetic pumping device as de- --sc1ibe.d in claim 1, whereinsaidfeleotric means comprise a source ofialternating current con- .nected in circuit with said electromagnetic means, andwherein half-wave rectifiers are in cluded in the circuit connections to saidielectromagnetic means, said rectifierseach passing-onehalf Wave of current to the electromagnetic means, thereby causing intermittent energization of the electromagnetic-means.

. den-electromagnetic pumping-device'as described inclaim 1,wherein said electrical-means compriseasource of A.-G. connected in circuit with the electromagnetic means, and wherein -half-Wave rectifiers are-included in the circuit connections to said electromagnetic means, said .rectifiers each passingone half-wavepi current alternately to the electromagnetic means thereby causing an intermittent energizationoi-said electromagnetic means, and wherein capacitance means are included in the; coil. circuits; said capacitance-means causing-a shift in the phase of the alternating current supplied to -the=electro- .magnetic means, ,thereby causing the electro- ,,magnetic means to be. successively-energized.

. 9. An electromagnetic;pumping device'as-described inclaim 1, wherein-said housing is com- =posed of two portions, the facing surfacesof said housing-portions being. spaced apart, and'wherein the peripheral marginal portion of the diaphragm extends withplay into. said space there- --by forming an annular slotleading into said pumping chamber between the-marginal diaphragm portion and the respective housing surface, oscillatory movement of the diaphragm to- ..wardsaid continuous surface-closing said annuylar ,slot, and oscillatory .movement in opposite direction opening saidslot.

-10. An electromagneticpumping device as described in claim 1, wherein said diaphragm comprises a plurality of. stacked flexible outer. and intermediate. discs, at least one, of saiddiscs made .of ferromagnetic material, at leastonev outer disc being a full disc havingat leastone aperture therein, eachintermediate disc havingat least one slot to reduce eddycurrent lossesandto .con-

duct. fluid, said, slots communicating with each aperture and said .fiuid. admission means, and

.wherein valve means are supportedv on said-diaphragm and, arranged to, close said apertures upon oscillatory movement ,of the diaphragm to- ..ward the curved. pole faces and -.to uncover the .,aperturesupon. oscillatory movement of the diaphragm away fromthepole ,faces.

11. An electromagnetic pumpingdevice as described in claim 10, wherein said housingjs, composed of two portions, and wherein saicldiaphragm is, fluid-tightly held alongits periphery between said housing portions.

"12. In an electromagnetic pumping device for pumping a fluid-in combination a housing, a pair of electromagnets mounted therein, each of said electromagnets comprising plurality of :scribed.in;iclaim hrwhereinreacn..of. saidien'o-zqs sconcentrically disposed; electromagnetic-m bers, each including a ferromagnetic core having a pole face and an exciting coil, the pole faces of the concentric electromagnetic members of each electromagnet and the respective concentric coils forming a substantially continuous surface, said surfaces being positioned to face each other spaced apart, an armature in form of a flexible circular diaphragm disposed between said surfaces to form a first pumping chamber between the diaphragm and one of said surfaces and a second pumping chamber between the diaphragm and the other surface, electrical means for alternately and intermittently energizing said coils progressively from the outermost coil to the innermost coil so as to cause the diaphragm to oscillate between opposite pole faces, thereby varying the capacities of said chambers, the coils of each electromagnet, when energized, attracting corresponding adjacent circular surface areas of the diaphragm in the sequence of the energization of said coils, fluid admission means arranged to communicate with said chambers and to admit fluid into one of the chambers upon oscillatory movement of the armature in one direction and into the other chamber upon oscillatory movement of the armature in the opposite direction, and a pair of fluid discharge means communicating with said chambers, one of said discharge means being arranged to discharge fluid from one of said chambers upon oscillatory movement of the armature in one direction and the other discharge means being arranged to discharge fluid from the others of said chambers upon oscillatory movement of the armature in the opposite direction.

13. In an electromagnetic pumping device for pumping a fluid, in combination a housing, an electromagnet mounted therein, an armature in form of a flexible diaphragm disposed within the housing spaced apart from the electromagnet and arranged to be attracted by the electromagnet when the same is energized and to return into its original position upon deenergization of the electromagnet, a piston supported on the diaphragm for movement in unison therewith, said housing including wall portions defining a compartment in which said piston is slidably guided for reciprocatory movement, said compartment including a pumping chamber formed by the piston and the Wall portions defining said compart ment, electric means for intermittently energizing said electromagnet thereby causing the diaphragm to oscillate and the piston t" vary the capacity of said pumping chamber, fiuid admission means arranged to communicate with said chamber and to admit fluid into said chamber upon oscillatory movement of the armature and the piston in one direction relative to the electromagnet, and fluid discharge means arranged to communicate with said chamber and to discharge fluid from said chamber upon oscillatory movement of the armature and the piston in the opposite direction.

14. In an electromagnetic pumping device for pumping a fluid, in combination a housing, a pair of electromagnets mounted within the housing spaced apart, each electromagnet including core means having a pole face thereon, the pole faces of the electromagnets facing each other, an armature in form of a diaphragm disposed between the pole faces of the electromagnet and arranged to oscillate relative to said pole faces upon alternating energization of the electromagnets, a piston supported on one side of the diaphragm for movement in unison therewith, said housing including wall portions defining a Q0111:

partment in which said piston is slidably guided for reciprocatory movement, said compartment including a first pumping chamber formed by the piston and the wall portions defining said compartment, a second pumping chamber being formed and confined by the other side of said diaphragm and the pole faces of the electromagnet facing the said diaphragm side, conduit means connecting the said pumping chambers, valve means included in said conduit means, said valve means being arranged to be normally closed and to be opened for passage of fluid from the second chamber to the first chamber in response to a predetermined fluid pressure in the second chamber, electric means for alternately and intermittently energizing said pair of electromagnets so as to cause the diaphragm and the piston to oscillate relative to the pole faces thereby alternately varying the capacities of said chambers, fluid admission means communicating with the second pumping chamber for admitting fluid to be pumped into the said chamber, and fluid discharge means communicating with the first pumping chamber for discharging fluid from the said chamber, said discharge means including second valve means normally closed and arranged to be opened for discharge of fluid in response to a predetermined fluid pressure in the first pumping chamber.

15. In an electromagnetic pumping device for pumping a fluid, in combination a housing, electromagnetic means having a plurality of independently magnetizable concentric portions mounted within the housing, said adjacent concentric portions forming a substantially continuous surface, armature means in form of a flexible circular diaphragm, said diaphragm being supported along its periphery within the housing and positioned to form a pumping chamber between the diaphragm and the adjacent continuous surface, electric means for alternately and intermittently energizing said concentric magnetizable portions progressively from the outermost portion to the innermost portion so as to cause the diaphragm to oscillate thereby varying the capacity of the pumping chamber, said concentric portions, when magnetized, attracting corresponding adjacent circular surface areas of the diaphragm in the sequence of the magnetization of said concentric portions, fluid admission means arranged to communicate with the pumping chamber and to admit fluid into a chamber upon oscillatory movement of the armature means in one direction, and fluid discharge means arranged to communicate with the pumping chamber and to discharge fluid from the chamber upon oscillatory movement of the armature means in opposite direction.

16. In an electromagnetic pumping device for pumping a fluid, in combination a housing, electromagnetic means mounted therein, said electromagnetic means comprising a plurality of concentric electromagnetic portions each having a core formed with a pole face and an exciting coil, armature means in form of a flexible diaphragm comprising a plurality of stacked flexible circular discs, at least one of said discs made of ferromagnetic material and having at least one radial slot to reduce eddy-current losses, said dia-. phragm being supported along its periphery her with the adjacent side of the diaphragm,

electrical means for alternately and intermittently energizing said coils progressively from the outermost coil to the innermost coil so as to cause the diaphragm to oscillate, thereby varying the capacity of said chamber, said concentric elec-- tromagnetic portions of the electromagnetic means, when energized, attracting corresponding adjacent circular surface areas of the diaphragm in the sequence of the energization of said concentric portions, fluid admission means arranged to communicate with the pumping chamber and to admit fluid into the chamber upon oscillatory movement of the armature means in one direction relative to said surface, and fluid discharge means arranged to communicate with the pumping chamber and to discharge fiuid from the chamber upon oscillatory movement of the armature means in opposite direction.

17. An electromagnetic pumping device as described in claim 16, wherein the cores of said concentric electromagnetic portions are formed by a plurality of annular core members concentrically arranged, each of said core members having a U-shaped cross-section, the open sides of said core members facing the diaphragm and receiving said exciting coils, and wherein said core members are radially slotted at least once to reduce eddy-current losses.

18. An electromagnetic pumping device as described in claim 16, wherein the cores of said concentric electromagnetic portions are formed by a plurality of annular core members concentrically arranged, each of said core members comprising a plurality of U-shaped, at least once radially slotted core elements nested one in another, the open side of said core members facing the diaphragm and receiving said exciting coils.

19. An electromagnetic pumping device as described in claim 16, wherein the cores of said electromagnetic portions are formed by a common ferromagnetic body having several annular concentric grooves, and wherein said exciting coils are fitted in said grooves, and wherein a hard insulation material fills the spaces between the grooves and the respective coils so as to form the said continuous surface.

20. An electromagnetic pumping device as described in claim 16, wherein the cores of said concentric electromagnetic portions are formed by a common ferro-magnetic body having several annular concentric grooves, and wherein said exciting coils are fitted in each one of said grooves.

21. Pin-electromagnetic pumping device as described in claim 20, wherein at least one face of said core body includes annular concentric recesses positioned between each two grooves for the coils.

22. An electromagnetic pumping device as described in claim 16, wherein the cores of said concentric electromagnetic portions are formed by a common ferro-magnetic body having several annular concentric grooves, and wherein said exciting coils are fitted in each one of said grooves, and wherein said core body is radially slotted at least once to reduce eddy-current losses.

23. An electromagnetic pumping device as described in claim 22, wherein said core body is laminated.

24. An electromagnetic pumping device as described in claim 16, wherein the cores of said concentric electromagnetic portions are formed by a plurality of annular core members concentrically arranged, each of said core members having a U-shaped cross-section, the open sides 2%) of said core members facing the diaphragm and receiving said exciting coils.

25. An electromagnetic pumping device as described in claim 24, wherein each of said core members comprises a plurality of U-shaped core elements nested one in another.

26. An electromagnetic pumping device as described in claim 25, wherein the arms of the core members formed by said nested core elements are reduced in cross-section toward the pole faces.

27. An electromagnetic pumping device for pumping a fluid, in combination a housing made of non magnetic material, electromagnetic means mounted therein, said electromagnetic means including a plurality of concentrically disposed electromagnetic portions, each of said portions comprising a ferro-magnetic ring core having a pole face and an exciting coil, adjacent coils and pole faces of said cores forming a substantially continuous surface, armature means in form of a flexible circular diaphragm, said diaphragm being mounted within the housing in a position relative to said continuous surface so as to form a pumping chamber between said surface and the adjacent side of the diaphragm, electric means for alternately and intermittently energizing said coils progressively to the outermost coil to the innermost coil so as to cause the diaphragm to oscillate thereby varying the capacity of said chamber, said concentric electromagnetic portions, When energized, attracting corresponding adjacent circular surface areas of the diaphragm in the sequence of the energize.- tion of said electromagnetic portions, spring means operatively connected with the other side of the diaphragm and biased to move the latter in a direction opposite to the direction of the magnetic attraction for retracting the diaphragm in the intervals between intermittent energization of said coils, fluid admission means arranged to communicate with said chamber and to admit fluid into said chamber upon oscillatory movement of the diaphragm in one direction relative to the electromagnetic means, and fluid discharge means arranged to communicate with said chamber and to discharge fluid from said chamber upon oscillatory movement of the armature means in opposite direction.

28. In an electromagnetic pumping device for pumping a fluid, in combination a housing made of nonemagnetic material, electromagnetic means mounted within the housing, said electromagnetic means including a plurality of concentrically disposed electromagnetic portions, each of said portions comprising a ierro-magnetic ring core having a pole face and an exciting coil, adjacent coils and pole faces of said cores forming a substantially continuous surface, armature means in form of a flexible circular diaphragm, said diaphragm being mounted within the housing in a position relative to said continuous surface so as to form a pumping chamber between the said surface and the adjacent side of the diaphragm, a piston supported on the opposite side of the diaphragm for movement in unison therewith, said housing including wall portions defining a compartment in which said piston is slidably guided for reciprocatory movement, said compartment including a second pumping chamber formed by the piston and the wall portions defining said compartment, electric means for alternately and intermittently energizing said coils progressively from the outermost coil to the innermost coil so as to cause the diaphragm to oscillate thereby varying the capacity of said pumping chambers, said concentric electroma netic portions, when energized, attracting corresponding adjacent circular surface areas of the diaphragm in the sequence of the energization of said concentric electromagnetic portions, fluid admission means arranged to communicate with said chambers and to admit fluid into one of the chambers upon oscillatory movement of the diaphragm in one direction and into the other chamber upon oscillatory movement of the diaphragm in the opposite direction, and a pair of fluid discharge means each communicating with one of said chambers, one of said discharge means arranged to discharge fluid from the respective chamber upon oscillatory movement of the diaphragm in one direction and the other discharge means being arranged to discharge fluid from the respective chamber upon oscillatory movement of the diaphragm in the opposite direction.

ANTON RYBA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,380,442 Trumble June '7, 1921 1,425,191 Garbarini Aug. 8, 1922 1,534,829 Behnke Apr. 21, 1925 15 2,253,206 Farrow Apr. 19, 1941 FOREIGN PATENTS Number Country Date 552,836 Germany June 28, 1930 

